The siege of Tsingtao was the attack on the German port of Qingdao (Tsingtao) during World War I by Japan and the United Kingdom. The siege was waged against Imperial Germany between 27 August and 7 November 1914. The siege was the first encounter between Japanese and German forces, the first Anglo-Japanese operation of the war, and the only major land battle in the Asian and Pacific theatre during World War I.

Qingdao, traditionally romanized as Tsingtao, is a city in eastern Shandong Province of China. Located on China's Yellow Sea coast, it is a major nodal city of the Belt and Road Initiative (BRI) that connects Continental and East Asia with Europe. It has the highest GDP of any city in the province. Administered at the sub-provincial level, Qingdao has jurisdiction over seven districts and three county-level cities. As of the 2020 census, Qingdao built-up area made of the seven urban districts was home to 7,172,451 inhabitants, making it the 15th largest city in China by population. Lying across the Shandong Peninsula and looking out to the Yellow Sea, it borders the prefecture-level cities of Yantai to the northeast, Weifang to the west and Rizhao to the southwest.